Turtles-own defines variables that belong to all turtles in a model. The variables are usually a trait or aspect specific to the turtle, like is-hungry? or energy. Like global variables and other agent variables, it must be defined at the top of your code, before any procedure definitions. It has the form of turtles-own [ variable1 variable2 ... ].You can define one variable or multiple, but they must all be within the brackets.

If you have defined multiple breeds of turtles, turtles-own will apply the variable to all breeds. However, you can define a variable for a specific breed by using <breed>-own, where is the name of your breed. For example, if you have already defined a breed of turtles by breed [birds bird], you can create a variable for only birds by using birds-own [wing-size].